In photography (and in movie and video production), it is desirable to capture events in a natural manner with minimal intervention and disturbance. Current state-of-the-art photographic or video apparatus even in its most simple "point and click" form, creates a visual disturbance to others and attracts considerable attention on account of the gesture of bringing the camera up to the eye. Even if the size of the camera could be reduced to the point of being negligible (e.g. no bigger than the eyecup of a typical camera viewfinder, for example), the very gesture of bringing a device up to the eye is unnatural and attracts considerable attention, especially in establishments such as gambling casinos or department stores where photography is often prohibited. Although there exist a variety of covert cameras such a camera concealed beneath the jewel of a necktie clip, cameras concealed in baseball caps, and cameras concealed in eyeglasses, these cameras tend to produce inferior images, not just because of the technical limitations imposed by their small size, but, more importantly because they lack a means of viewing the image. Because of the lack of a viewfinder., investigative video and photojournalism made with such cameras suffers from poor composition.
It appears that apart from large view cameras upon which the image is observed on a ground glass, most viewfinders present an erect image. See, for example, U.S. Pat. No. 5,095,326 entitled "Keppler-type erect image viewfinder and erecting prism". In contrast to this fact, it is well-known that one can become accustomed, through long-term psychophysical adaptation (as reported by George M. Stratton, in Psychology Review, in 1896 and 1897) to eyeglasses that present an upside-down image. After wearing upside-down glasses constantly for eight days (keeping himself blindfolded when removing the glasses for bathing or sleeping) Stratton found that he could see normally through the glasses. More recent experiments, as conducted by and reported by Mann, in an MIT technical report Mediated Reality, medialab vismod TR-260, (1994), (the report is available in http://wearcam.org/mediated-reality/index.html) suggest that slight transformations such as rotation by a few degrees or small image displacements give rise to a reversed aftereffect that is more rapidly assimilated by the wearer, and that such effects can often have a more detrimental effect on performing other tasks through the camera as well as more detrimental flashbacks upon removal of the camera. These findings suggest that merely mounting a conventional camera such as a small 35 mm rangefinder camera or a small video camcorder to a helmet, so that one can look through the viewfinder and use it it hands free while performing other tasks, will result in poor performance at doing those tasks while looking through the camera viewfinder. Moreover, these findings suggest that doing tasks while looking through the viewfinder of a conventional camera, over a long period of time, may give rise to detrimental flashback effects that may persist even after the camera is removed. This is especially true when tile tasks involve a great deal of hand-eye coordination, such as when one might, for example, wish to photograph, film, or make video recordings of the experience of eating or playing volleyball or the like, by doing the task while concentrating primarily on the eye that is looking through the camera viewfinder. Indeed, since known cameras were never intended to be used this way (to record events from a first-person-perspective while looking through the viewfinder) it is not surprising that performance is poor in this usage.
Part of the reason for poor performance associated with simply attaching a conventional camera to a helmet is the induced parallax and the failure to provide an orthoscopic view. Even viewfinders which correct for parallax, as described in U.S. Pat. No. 5,692,227 in which a rangefinder is coupled to a parallax error compensating mechanism only correct for parallax between the viewfinder and the camera lens that is taking the picture, but do not correct for parallax between the viewfinder and the image that would be observed with the naked eve while not looking through the camera.
Traditional camera viewfinders often include the ability to overlay virtual objects, such as camera shutter speed, or the like, on top of reality, as described in U.S. Pat. No. 5,664,244 which describes a viewfinder with additional information display capability.
Open-air viewfinders are often used on extremely low cost cameras, as well as on some professional cameras for use at night when the light levels would be too low to tolerate any optical loss in the viewfinder. Examples of open-air viewfinders used on professional cameras, in addition to regular viewfinders, include those used on the Grafflex press cameras of the 1940s (which had three different kinds of viewfinders), as well as those used on some twin-lens reflex cameras. While such viewfinders, if used with a wearable camera system, would have the advantage of not inducing the problems such as flashback effects described above, they would fail to provide an electronically mediated reality. Moreover although such open air viewfinders would eliminate the parallax between what is seen in the real world and what is seen in the real world looking through the viewfinder, they fail to eliminate the parallax error between the viewfinder and the camera.
A manner of using a plurality of pictures of the same scene or object, in which the pictures were taken using a camera with automatic exposure control, automatic gain control, or the like has been proposed in `PENCIGRAPHY` WITH AGC: JOINT PARAMIETER ESTIMIATION IN BOTH DOMAIN AND RANGE OF FUNCTIONS IN SAME ORBIT OF THE PROJECTIVE-WYCKOFF GROUP, published by S. Mann, in M.I.T. (medialab vismod) tech report TR-384, December, 1994, and later published also in Proceedings of the IEEE International Conference on Image Processing (ICIP-96), Lausanne, Switzerland, Sep. 16-19, 1996, pages 193-196, the contents of which are incorporated herein by reference. (The report is also available on a world wide web site: http://wearcam.org/icip96/index.html as a hypertext document.) This report relates to a manner of camera self-calibration in which the unknown nonlinear response function of the camera is determined up to a single unknown scalar constant. Therefore, once the camera is so understood, it may be used, within the context of the method, as a quantigraphic light measuring instrument. As each pixel of the camera then becomes a light measuring instrument, successive pictures in a video sequence become multiple estimates of the same quantity once the multiple images are registered and appropriately interpolated. The measurement from a plurality of such estimates gives rise to knowledge about the scene sufficient to render pictures of increased dynamic range and tonal fidelity, as well as increased spatial resolution and extent. In this way a miniature video camera as may be concealed inside a pair of eyeglasses may be used to generate images of very high quality, sufficient for fine-arts work or other uses where good image quality is needed.